Field of the Invention
The present invention relates to wireless communication, and more particularly, to a circular array antenna.
Discussion of the Related Art
In modern times, a demand for a service that transmits and receives mass data such as video, voice, and the like at a high speed has been rapidly increased. As a result, in recent years, in order to increase a data capacity in a high-speed point-to-point system under a visible distance environment, a research into communication using an orbital angular momentum (OAM) has been actively made worldwide in Sweden, Italia, Japan, Australia, and the like.
The OAM was predicted by Poynting in 1909 and thereafter, introduced in an optical field in 1992 and thus an active research has been in progress. Further, an applicability of the OAM in electromagnetic wave and a microwave fields was presented in 2007.
As a device for generating an OAM mode, a metallic reflection plate and an exciton element are used, but the metallic reflection plate and the exciton element has a form of a 3D structure, and as a result, the metallic reflection plate and the exciton element are influenced by wind or rainfall, snowfall, and the like.
Accordingly, in the technical field, an antenna device not influenced by the wind or the rainfall, the snowfall, and the like is required.